Trastuzumab emtansine may lead to serious heart problems, including heart failure. Past use of certain other anti-cancer drugs (including anthracyclines such as doxorubicin) may increase your risk of heart problems. Tell your doctor right away if you have any symptoms of heart failure, including shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain.

Trastuzumab emtansine can cause serious (possibly fatal) harm to an unborn baby if used during pregnancy. Discuss reliable forms of birth control with your doctor.

Trastuzumab emtansine is used to treat certain types of breast cancer. This medication is used to treat tumors that produce more than the normal amount of a certain substance called HER2 protein.

This medication is called a monoclonal antibody and microtubule inhibitor conjugate. Trastuzumab emtansine works by attaching to the HER2 cancer cells and blocking them from dividing and growing. It may also destroy the cancer cells or signal the body (immune system) to destroy the cancer cells.

This monograph is about the following trastuzumab emtansine products: trastuzumab emtansine, ado-trastuzumab emtansine.

This medication is given by slow injection into a vein by a health care professional. It is given as directed by your doctor, usually once every 3 weeks. Your first infusion will be given over at least 90 minutes.

The dosage, the speed of your injection, and the length of time you receive trastuzumab emtansine is based on your body weight, medical condition, and response to treatment.

To get the most benefit from this medication, do not miss any doses. To help you remember, mark the days on the calendar when you need to receive the medication.

Your doctor may prescribe other medications (such as acetaminophen, diphenhydramine) for you to take before the start of your treatment to help prevent serious side effects.

Diarrhea, redness/irritation at the injection site, dizziness, muscle/joint/back pain, stomach/abdominal pain, constipation, trouble sleeping, nausea, vomiting, mouth sores, dry mouth, changes in taste, and loss of appetite may occur. Nausea and vomiting can be severe. In some cases, your doctor may prescribe medication to prevent or relieve nausea and vomiting. Eating several small meals, not eating before treatment, or limiting activity may help lessen some of these effects. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

bone pain

increased coughing

swelling of the hands/ankles/feet

unusual tiredness

severe headache

tingling/numbness (such as in the hands, feet, leg)

mental/mood changes

fast/pounding heartbeat

muscle cramps

easy bruising/bleeding

This drug has caused very serious (rarely fatal) bleeding. Get medical help right away if you develop symptoms of very serious bleeding, including:

weakness on one side of the body

slurred speech

vision changes

confusion

severe stomach/abdominal pain

trouble breathing

vomit that is bloody or looks like coffee grounds

black/tarry stool

This medication may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as fever, chills, persistent sore throat, cough).

This medication can sometimes cause a serious infusion reaction with serious lung problems. Immediately tell your doctor of the following side effects that occur while this drug is being given or within 24 hours after your treatment is finished, such as chills, fever, flushing, wheezing, shortness of breath, nausea, headache, dizziness, fainting, rash, and weakness.

Trastuzumab emtansine can commonly cause a rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Therefore, tell your doctor right away if you develop any rash.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

rash

itching/swelling (especially of the face/tongue/throat)

severe dizziness

trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using trastuzumab emtansine, tell your doctor or pharmacist if you are allergic to it; or to any trastuzumab emtansine, trastuzumab, or trastuzumab-hyaluronidase products; or if you have any other allergies. This product may contain inactive ingredients which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Trastuzumab emtansine can make you more likely to get infections or may worsen any current infections. Therefore, wash your hands well to prevent the spread of infection. Avoid contact with people who have infections that may spread to others (such as chickenpox, measles, flu). Consult your doctor if you have been exposed to an infection or for more details.

Do not have immunizations/vaccinations without the consent of your doctor. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

To lower the chance of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports.

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially heart problems (such as heart failure).

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using trastuzumab emtansine. Trastuzumab emtansine may harm an unborn baby. Women should ask about reliable forms of birth control while using this medication and for 7 months after stopping treatment. Men should ask about reliable forms of birth control while using this medication and for 4 months after stopping treatment. If you or your partner becomes pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breast-feeding is not recommended while using this drug and for 7 months after the last dose. Consult your doctor before breast-feeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If you will be using an anthracycline (such as doxorubicin) after stopping trastuzumab emtansine treatment, if possible, wait at least 7 months.

Other medications can affect the removal of trastuzumab emtansine from your body, which may affect how trastuzumab emtansine works. Examples include azole antifungals (such as itraconazole, ketoconazole), clarithromycin, HIV protease inhibitors (such as atazanavir, ritonavir), nefazodone, telithromycin, among others.

Trastuzumab emtansine is very similar to trastuzumab and trastuzumab-hyaluronidase. Do not use a trastuzumab or trastuzumab-hyaluronidase product while using a trastuzumab emtansine product.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

Lab and/or medical tests (such as heart exams, platelet counts, liver function, bilirubin level) should be done before you start using this medication and while you are using it. A pregnancy test should also be done before starting treatment. Keep all medical and lab appointments. Consult your doctor for more details.

For the best possible benefit, it is important to receive each scheduled dose of this medication as directed. If you miss a dose, contact your doctor or pharmacist right away to establish a new dosing schedule.

HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

Information last revised July 2019.

Copyright(c) 2019 First Databank, Inc.

Selected from NATIONAL DRUG DATA FILE (NDDF) data included with permission and copyrighted by First Databank, Inc., 2019. This copyrighted material has been downloaded from a licensed data provider.

The above information is intended to supplement, not substitute for, the expertise and judgment of your health care professional. You should consult your health care professional before taking any drug, changing your diet, or commencing or discontinuing any course of treatment.